replica install: enforce --server arg
    
    When the --server option is provided to ipa-replica-install (1-step
    install), make sure that the server offers all the required roles
    (CA, KRA). If it's not the case, refuse the installation.
    
    Note that the --server option is ignored when promoting from client to
    replica (2-step install with ipa-client-install and ipa-replica-install),
    meaning that the existing behavior is not changed in this use case:
    by default the host specified in default.conf as server is used for
    enrollment, but if it does not provide a required role, another host can
    be picked for CA or KRA setup.
    
    Fixes: https://pagure.io/freeipa/issue/7566
    Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Mohammad Rizwan Yusuf <myusuf@redhat.com>